Small tools, honest defaults
DevKit Lab is a collection of ten developer utilities that do one thing each, do it well, and get out of your way. It was built because the equivalent tools on the web mostly fall into two camps: either they are bloated with ads, trackers, and sign-up prompts, or they upload your data to a server for processing — and neither is what you want when you are pasting in a JWT from production or checking a regex against a customer record.
The principle
Every tool here runs entirely in your browser. That is not a marketing line — it is the literal technical design. There is no backend performing conversions. Open the Network tab in your browser DevTools and you will see that no requests fire while you use a tool. The only network activity is loading the page itself. After that, every keystroke, every decode, every generated UUID happens on your own machine using standard JavaScript primitives.
That design choice is what makes the promises on the homepage real. When we say your data never leaves your browser, we mean the code cannot send it anywhere because no code has been written to do so.
What is included
There are currently ten tools: a JSON formatter, Base64 encoder, URL encoder, regex tester, timestamp converter, UUID generator, password generator, JWT decoder, diff checker, and minifier. Each has its own page with a focused interface and a short guide underneath explaining the underlying concept for people who want to understand, not just use.
What is not included
There is no account system. There is no payment tier. There is no rate limit. There is no "free plan" gating features you need. If a tool exists on the site, the full version is the one you see. If something is useful, we will add it; if it would require tracking or a backend, we probably will not.
How this stays free
The site is supported by unobtrusive display advertising. Ads are kept out of the tool interface itself — they appear on the page, not inside the work area, and never interrupt what you are doing. No ad network receives your tool inputs because the tool inputs never leave your browser. If you find the ads bothersome, a content blocker will hide them and the tools will continue working identically.
Feedback
If you find a bug, have a tool suggestion, or want to point out where something could be clearer, get in touch. The site is small enough that individual feedback actually shapes what gets built next.